Role of the Insula in Visual and Auditory Perception

Abstract

The insular cortex has long been associated with playing a critical role in perception especially of auditory and visual stimulus. Its role in auditory and visual perception has been well described through literature; however, the specific role of the insula is convoluted in the fact that it is difficult to study the specific function of the insula. It is hard to study its role because most of its complex functions are part of and rely on a complex network of multiple cortices. Imaging studies such as fMRI have been limited to measuring activation of these networks and have not been able to focus specifically on just measurements of the insula (Sterzer and Kleinschmidt, Brain Struct Funct 214:611–622, 2010). Some insights into studies have been conducted such as selective human stimulation of the insula. These studies have produced numerous responses such as somatosensory and auditory sensation (Mazzola et al., J Clin Neurophysiol 34:307–314, 2017). Its specific role is further complicated by its role in multimodal sensory integration. At times the insula’s major role of “decision-making” and audio/visual perception are synonymous. Some of its implicated roles in auditory perception are sound motion, frequency recognition, and pattern recognition (Mullan and Penfield, AMA Arch Neurol Psychiatry 81:269–284, 1959; Neff, Ann Otol Rhinol Laryngol 66:506–513, 1957; Colavita Physiol Behav 12:215–218, 1974). Some implicated roles of visual perception are word recognition and perception of facial intention (Dehaene et al., Nat Neurosci 4:752–758, 2001; Pessoa et al., Neuroimage 28:249–255, 2005). In this chapter, we will further investigate the insular cortex’s role in each of these functions as well as others that help shape what we consciously perceive visual and auditory stimulus.